67406981 has 2 divisors, whose sum is σ = 67406982. Its totient is φ = 67406980.

The previous prime is 67406957. The next prime is 67407001. The reversal of 67406981 is 18960476.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 49420900 + 17986081 = 7030^2 + 4241^2 .

It is a cyclic number.

It is not a de Polignac number, because 67406981 - 2¹⁸ = 67144837 is a prime.

It is a super-2 number, since 2×67406981² = 9087402175068722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (67406081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33703490 + 33703491.

It is an arithmetic number, because the mean of its divisors is an integer number (33703491).

Almost surely, 2^67406981 is an apocalyptic number.

It is an amenable number.

67406981 is a deficient number, since it is larger than the sum of its proper divisors (1).

67406981 is an equidigital number, since it uses as much as digits as its factorization.

67406981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72576, while the sum is 41.

The square root of 67406981 is about 8210.1754548852. The cubic root of 67406981 is about 406.9755250934.

The spelling of 67406981 in words is "sixty-seven million, four hundred six thousand, nine hundred eighty-one".